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Re: Deleting duplicates from a list

• To: mathgroup at smc.vnet.net
• Subject: [mg76000] Re: [mg75940] Deleting duplicates from a list
• From: Adriano Pascoletti <adriano.pascoletti at dimi.uniud.it>
• Date: Mon, 14 May 2007 05:48:32 -0400 (EDT)
• References: <200705140725.DAA22641@smc.vnet.net>

This is the unsorted union problem, which can be efficiently solved  
using Sow and Reap (see Help Browser > Reap > Further Examples)

In[8]:=UnsortedUnion[x_] := Reap[Sow[1, x], _, #1 & ][[2]]

In[9]:=UnsortedUnion[{8, 8, 11, 11, 19}]

Out[9]={8, 11, 19}

Adriano Pascoletti

On 14 mag 2007, at 09:25, Raul Martinez wrote:

> Hi all,
>
> I have a list, e.g., {8, 8, 11, 11, 19}. I want to eliminate all
> duplicates so the list becomes {8, 11, 19}. Can anyone suggest a
> command that will do this?
>
> TIA,
>
> Raul Martinez
>

• Follow-Ups:
  • Re: Re: Deleting duplicates from a list
    • From: Murray Eisenberg <murray@math.umass.edu>

• References:
  • Deleting duplicates from a list
    • From: Raul Martinez <raulmart@mac.com>